Antenna design for mobile devices is to a great extent a matter of fashion, and different antenna concepts are becoming popular as they allow for novel industrial designs. Also, many handsets use PIFA, Loop or ILA type antennas, but these antennas call for radio frequency (RF) transparent covers in order not to impact the radiation properties of the antennas. In many cases, it may be desirable to use as much metal as possible on the outside of the device. The robustness of the metal may help to reduce wear and tear and to provide a feeling of quality.
However, metal covers introduce new challenges to antenna design and user interaction issues. Also, integration of the metal covers with other antennas may be difficult.